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Science Biology B1 OCR Gateway flashcards
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- 1Fitness and Health.Blood pressure:
Arteries carry blood away from the heart.
Blood in the arteries are under pressure because of the contractions of the heart muscles. This allows blood to reach all of the parts in the body. - 2Measuring blood pressure.Mmhg (millimetres or Mercury) two measurments: systolic pressure; the higher measurment when the heart beats pushing blood through the arteries diastolic pressure; the lower measurment when the heart rests between beats
- 3Increase of blood pressureSmoking
Being overweight
Drinking a lot of alcohol
Stress
You can reduce it by a balanced diet and regular exercise. - 4Fitness versus healthFitness is the ability to do physical activity. Health is the amount of freedom from disease.
- 5Measuring fitnessStrength
Stamina- how long you can go
Flexibility
Agility- how easily someone can move
Speed
Cardiovascular efficiency- how well a persons circulatory system works - 6Smoking4,000 chemicals.
Nicotine- the addictive substance in tobacco smoke.
Carbon monoxide - 7Heart diseaseBlood vessels called the coronary arteries supply blood to the heart muscles. If they become blocked, a heart attack can happen.
- 8Heart attacksFatty deposits build up in the coronary arteries.
A blood clot can form on a fatty deposit.
The blood clot can block a coronary artery.
Some heart muscle cells do not get the oxygen and nutrients they need.
These cells start to die. - 9Factors for heart diseaseSmoking.
High blood pressure.
High levels of salt in the diet.
High levels of saturated fat in the diet.
High levels of salt in the diet can lead to increased blood pressure.
High levels of saturated fat in the diet lead to a build of cholesterol in the arteries, causing a plaque and narrowing of the arteries. - 10Human health and diet.A balanced diet.
carbohydrates=simple sugars=high energy source.
Fats=fatty acids and glycerol=high energy source.
proteins=amino acids=growth and repair. - 11A balanced diet will also includeMinerals, such as iron, to make the haemoglobin needed in red blood cells.
Vitamins, such as, which prevents a disease called scurvy.
Fibre, which prevents constipation.
Water. - 12Underweight and overweightBeing overweight causes:
Diabetes.
Arthritis.
Heart disease.
Breast cancer. - 13BMIBMI = mass in kg ÷ (height in m)2
For example, BMI = 60 ÷ (1.7)2 = 60 ÷ 2.89 = 20.8 - 14KwashiorkorProtein deficiency.
- 15EAREAR in g = 0.6 * body mass in kg
- 16Staying Healthy.Pathogens are organisms that cause disease. They include microorganisms such as bacteria, viruses, fungi and protozoa.
Bacteria = Cholera
Viruses = Flu
Fungi = Athlete's foot
Protozoa = Malaria - 17ParasitesParasites are an organism that live on or in a host organism.
- 18MalariaMalaria is a disease caused by a protozoan, a type of single-celled organism. The malaria parasite is spread from person to person by mosquitoes. These insects feed on blood and the malaria parasite is passed on when the mosquito takes a meal. Organisms that spread disease, rather than causing it themselves, are called vectors. The mosquito is the vector for malaria.
- 19Infectious and non-infectious diseasesSome diseases are not caused by pathogens and so are not infectious. For example:
scurvy is caused by vitamin C deficiency
anaemia is caused by iron deficiency
diabetes and cancer are disorders of the body. - 20CancerA cancer happens when cells begin to divide out of control. They form tumours that can sometimes be felt as an unusual lump in the body.
Diet and lifestyle can increase the risk of developing certain cancers. For example:
smoking increases the risk of lung cancer
using sunscreen reduces the risk of skin cancer
eating more fruit and vegetables reduces the risk of bowel cancer. - 21ImmunityOnce inside the body, pathogens reproduce. Viruses reproduce inside cells and damage them, while escaping to infect more cells. Bacteria produce toxins - poisons. Cell damage and toxins cause the symptoms of infectious diseases.
Once pathogens enter the body, the immune system destroys them. White blood cells are important components of the immune system. - 22White blood cells.White blood cells can:
engulf pathogens and destroy them
produce antibodies to destroy pathogens
produce antitoxins that neutralise the toxins released by pathogens.
Pathogens contain certain chemicals that are foreign to the body, called antigens. Some white blood cells can make antibodies. These are proteins that have a chemical 'fit' to a certain antigen. When a white blood cell with the appropriate antibody meets the antigen, it reproduces quickly and makes many copies of the antibody to neutralise the pathogen. - 23Immunity continuedOnce you have been infected with a particular pathogen and produced antibodies against it, some of the white blood cells remain. If you become infected again with the same pathogen, these white blood cells reproduce very rapidly and the pathogen is destroyed. This is active immunity because you make your own antibodies.
Sometimes you may be treated for infection by an injection of certain antibodies from someone else. This is passive immunity because you receive antibodies, rather than make them yourself. - 24DrugsDrugs are substances that cause changes to the body. Antibiotics are drugs that kill bacteria, but not viruses. Antivirals are drugs that prevent viruses reproducing.
New medical drugs have to be tested to ensure that they work, and are safe, before they can be prescribed.
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- GCSE (Biology B1 OCR ) Science Fichas sobre Science Biology B1 OCR Gateway flashcards, creado por Eloise Fardell el 15/04/2015.
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